Preheat oven to 350°. Grease and flour two 9-in. round baking pans. In a large bowl, cream the butter, peanut butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Beat in vanilla. Combine the flour, baking powder and salt; gradually add to peanut butter mixture alternately with milk, beating well after each addition.,______,For frosting, in a small bowl, beat butter and peanut butter until smooth. Add the vanilla, confectioners' sugar and enough milk to achieve spreading consistency.,Place one cake layer on a serving plate; spread with jelly. Top with the remaining cake layer; frost top and sides of cake with frosting. Garnish with additional jelly and peanuts, if desired.